Sutures are thread-like strands or fibers used during surgery to sew together parts of the human body. When sewing together parts of the body, a surgeon will generally insert the suture into a thin, elongated surgical tool known as a "suture passer" and pass the suture and suture passer through the body to form a series of stitches. If the portions of the body being sewn together undergo considerable stress, it may be necessary to use several strands of suture to adequately sew the body portions together.
Conventional suture passers are rigid stainless steel rods of approximately 1/8 inch in diameter and 9 inches in length. The leading edge of the rod is ground to a point, as illustrated in FIG. 4, and includes a small aperture through the ground portion for threading a suture therethrough. To drill an aperture in the suture passer of sufficient size for accepting a suture, the suture passer should be 1/8 inch or more in diameter.
Conventional suture passers such as described above and illustrated in FIG. 4 are designed to function as drill bits as well as a suture passers. Although a surgeon can readily pass a suture passer through soft tissue or fibrous tissue by merely applying forward pressure to the suture passer, it is necessary to drill a passageway through bone before passing a suture and suture passer therethrough. Conventional suture passers are designed to be attached to a drill and used as a drill bit to drill a passageway through bone. When the leading edge of the suture passer has passed through the bone and out the back side of the passageway, the surgeon will thread a suture through the aperture of the suture passer. The suture passer is then withdrawn through the passageway, pulling the suture from the back side to the front side of the passageway. Alternately, a separate drill bit may be used to create a passageway. The suture passer is then merely inserted through the passageway to receive a suture at the back side of the passageway and pull it to the front side of the passageway. It is also possible to first thread the suture passer and insert it through the passageway with the suture in place when the passageway has been pre-drilled.
It is preferred that suture passers be at least 7 to 9 inches long. Passageways through bones may be up to 31/2 inches long. It is necessary to have adequate length to allow the leading edge of the suture passer to extend beyond the passageway to be threaded. The trailing end of the suture passer may have to pass through soft tissue on its way to the bone passageway and additionally must provide adequate room for the surgeon to handle the suture passer.
Although conventional suture passers work well for sewing together large bone segments in accessible areas, they are not well suited for sewing together ligaments or bones in confined areas, such as knee and shoulder joints. Because conventional suture passers are rigid instruments, they cannot be easily manipulated within the knee or shoulder joint to maneuver around anatomical parts or follow curved pathways. Sewing together ligaments or bones in these areas using arthroscopic surgery (in which only small incisions are made and the surgeon views the inside of the joint through a special view instrument known as an "arthroscope") has not been possible using conventional suture passers.
The unacceptability of conventional suture passers for use in areas which require flexibility has led to a number of makeshift surgical techniques for passing sutures through ligaments or bones in these areas. Many surgeons fasten loops at the end of a single wire and pass the wire through the ligament or bone needed to be connected. This technique is undesirable, however, as the bends which form in the wire at the loops are often sharp and capable of hanging up on soft tissue when passing through a knee joint. As minimizing damage to soft tissue is important for reducing patient recovery time, it is desirable to avoid damage to such tissue whenever possible.
Another drawback to this makeshift wire technique, as well as to conventional suture passers, is the inability to readily pass multiple sutures through part of the body at one time. Large ligaments often undergo sufficient stress to require multiple strands of sutures to repair them when they are torn. Consequently, it is advantageous to be able to pass multiple strands of suture through such ligaments with a single pass of a suture passer.